Transmission



Oct. v11, 1932. H; w. LEwls y 1,882,222

TRANSMISSION Filed sept. 9, 1930 4 sheets-sheet 1 H .I Q KQ [La u bg ma lq gg n L sg L A U0 w l w W "5 Q w D MV- a y s l M f i a Y f /llz'x 1 m w Se Q l s;

1NVENToR. Han/ara W zw/5 ATTORNEYS.

Oct. 1l, 1932. H. w. LEWIS TRANSMISSION Filed Sept. 9, 1930 4 Sheets-Sheet 2 INVENTOR. l Hon/ara l/l/ew/s oct@ 11; 1932. H. w. LEWIS TRANSMISSION Filed sept. 9f193o 4 speets-sheet- 5 IN1/EN ToR. #0n/0rd W ew/5.

ATTORNEYS.

Oct. 11, 1932. H. wjLEwls TRANSMISSION Filed sep. 9. 195o 4 sheets-sheet 4 .lmmlmHhH Howard W zw/I5 l @Mbfy t ATTORNEYS.

.Patented ocr. 11, 1932 nowaan w. Lawns, or Ysan FRANCISCO; CALIFORNIA TRANSMISSION i Application med September 9, 1930. Serial No. 480,708.

This inventionrelates to transmissions and is particularly a plicable to transmissions in which the spee ratio between a driving element and a driven element can be varied.

A In transmissions commonly employed in automobiles and the like a gear train is provided for"coupling a driving shaft with a driven shaft and at least one gear of the gear train `is so arranged that it can be replaced by another gear of diierent size to change the speed ratio between the shafts'. In transmissions of this' type it is necessary to remove at least one gear of the gear train out of meshing engagementwiththe remaining.

gears and tosubstitute another gear of different size for the removed gear whenever it is desired to change the s eed ratio.

To change thedirection of rotation of the driven shaft it is necessary to change the number of gears in the train. Each time a change is made in the transmission the coupling between the drivingshaft andthedriven shaft must be made inoperative, thus necessitating a clutch or its equivalent in the trans- 26 mission; i The operator of an automobile having a transmission of this t e must be constantly alert during the shiftlng of gears on account of the relativel large number of operations l 30 required. Whi e the operator Vis preoccupied with the manipulation of the shift le'ver and the clutch pedal he must steer the automobile with one hand and although one foot is free to operate the brakes of the vehicle, there is no way to accelerate the speed of the vehicle -while the gears are in neutral -position orY while the clutch is disengaged. This in.

ability to accelerate while shifting gears increases trafiic congestion and is `sometimes 40 the direct cause of an accident.

Transmissions of this type are comparatively expensive to manufacture. The clutcl faces are subject to wear and the .teeth of the' movable geararesometimes stripped thereby making the upkeep high. Perhaps the most serious objection, "however, is the inconvenience of shifting and the noise attendant upon the shifting operation.

My invention has for its main object the elimination of the disadvantages mentioned.

In its preferred form the invention comprises a transmission in which all ofthe gears of a gear train'areconstantly in meshing engagement. No shifting of ears is necessary to v vcha-nge thespeed Lratio tween the driving and riven shafts or to chan e the direction of rotation of the driven sha No clutch is required and the numberof parts inthe trans-L mission is reduced t0 a minimum. f

.A further object is to provide ya transmission in which the speed ratio can be varied adually throughout the rang between its imiting values. v

Another object is to provide a transmission in which the speed ratio can be varied without uncou ling the driving and driven shafts,

A still urther object is to provide a transmission which is relatively silent at all times.

A still further object is to provide a transmission in which the speed ratio can be easily andv conveniently changed with a minimum of manual operations.

Another object is to provide'a transmission which is reliable and practical and which is economical to manufactura.

These and other objects are attained in the embodiment of theinvention illustrated in the accompanyingdrawings in which:

Fig. 1 is a vertical longitudinal cross section of a transmission incorporating the featuresof this invention. e

Fig. 2 is a cross section taken 'on the line 2-2 of Fig. 1.

Fig. 3 is a cross section taken on the line 3-3 of Fig. 1.

F Fig. 4 is a cross section taken on line 4-4 of 1g. f Y Fi 5 is a cross section taken on line 5-5 of Fig. 1, with parts of the device broken away. 90

- Flg. 6 is a cross section taken on line'6-6 of Fig. 5.

'Figa-Vs a diagrammatic view Iof certain Huid conduits utilized in a preferred form of the invention.

Fig. 8 is an elevational view similar to Fig. 5 of a modification of certain valves employed tlc control the flow of duid in the fluid conuits. i

Fig. 9 is a vertical cross section of the valve 100 shown in Fig. 8 and illustrates also one form lof actuating mechanism for the val-Ves.

this invention comprises a pair of'gear trains interconnecting a driving shaft and a driven shaft, one of said gear trains tending to r0- tate the driven shaft in one direction and the other of said gear trains tending to rotate the driven shaft in the opposite direction. Means are provided for disabling the coupling effect of each of the gear trains whereby either one 'of the gear trains can control the movement of the drivenshaft while the other car train idles.

Pre erably, the disabling means ofthe separate gear trains are relative] complementary to one another, that is, the increase in the` degree of idleness of one gear train is accompanied by a corresponding increase 1n effectiveness of the other gear. traln. When one gear train is exclusively effective the driven shaft rotates at its highest velocity ascompared with the driving shaft 1n a certaln d1- rection, say clockwise, and when the. other gear train is exclusively effective the drlven shaft rotates at its maximum relative velocity in the other direction, or counterclockwise. The effectiveness of the gear trams can be varied gradually in complementary relationship to one another by the control means so that for intermediate ,settings of the same the velocity of thedriven shaft can be varied from maximum inone direction down to zero velocity and up to maximum velocity in the other direction.

Referring now to the drawings I have shwn a driving shaft 16 and a driven shaft:

17 and interconnecting these shafts are a lurality Vof gears mounted in a housing 18.

igidly secured to shaft16 to rotate therewith is a plate 19 and plate 19 is in turn connected to a block 21 mounted for rotational movement within housing 18. vInterconnecting block 21 and shaft 17 is an epicyclic gear train comprising a sun gear 22 'and a pair of planet gears 23 and 24. Suitable recesses are formed in block 21 for the reception of gears 22, 23 and 24 and gears 23 and 24are Journaled in bearings supported byblock 21and plate 19 for normally idle rotation within their respective recesses. Gear 22 is keyed to shaft 17 and meshes with gears (23 and 24. Upon rotation of shaft 16, plate 19 and block `21 rotate therewith and gears 23 and24 are y carried around by block 21. Assuming that planet gears 23 and 24 are unrestrained and are free to rotate in their respective bearings, these gears will roll idly along the periphery of gear 22 without imparting rotational gear 22 will be rotated with movement to gear 22 andshaft 17therefore will remain stationary. If, however, planet gears 23 and'24 are locked against rotation,

block 21. Similarly, if gears 23 and 24 are only partly restrained against rotation, gear 22 will rotate at an intermediate velocity. Shaft 17 is journaled in suitable bearings 26 and 27 which permit relative rotation of shaft 17 with respect to shaft 16 and plate 19.

A second 'epicyclic gear train is disposed within recesses in block 21 and comprises a sun gear 28 anda pair of planet gears 29 and 31. Planet gears 29 and 31 are mounted in bearingsin block 21 in a manner similar to the manner in which gears 23 and 24 are mounted and their action on sun gear 28 is smilar tothat which has been explained in connection with the first epicyclic gear train. Gear 28 is keyed to a sleeve 32 surrounding shaft 17 having a bearing 33 journaled in one wall of a gear .housing 34. lSleeve 32 extends Within housing 34 and has keyed thereon agear 36 which meshes with a pair of idler pinions 37 and 38. Formed integrally with pinions 37 and 38 are pinions 39' and 41 respectively which are in 'meshing engagement with a gear 42 which is fixed on shaft .17.

The gears mounted in housing 34 constitute a reversing reduction gear train and' shaft 17 is rotated in the reverse direction by gear 28 as compared with the direction of rotation imparted to itdby gear 22. Motion is transmitted from gear 28, through sleeve 32, gear 36, pinions 37 and 38, pinions 39 and 41, gear 42 and shaft 17. Assuming that block 21 is rotating in a clockwise direction, as viewed from the right in Fig. 1, and that planet gears 23 and 24 are locked against rotation, gear 22 will carrying shaft 17 with it, gear 42 will be ro-' tated in a clockwise direction and thru pinions 39, 41'and 37, 38 gear 36'will be rotated 1n a with it sleeve 32 and gear 28. Gear 28, therefore, will rotate in a counterclockwise direction within block 21 which is rotating in a clockwise direction and planet gears 29 and 31 will roll idly about the periphery of gear 28. When .planet gears 23 and 24 are free to rotate, however, and planet gears 29 and 31 are locked against rotation, shaft 17 will be rotated by gear 28 in a counterclockwise direction upon clockwise rotation of block 21 and gear 22 will rotate in a counterclockwise direction with planet idly nv its surface.

Thus, shaft 17 can be rotated in either a clockwise or a counterclockwise direction by counterclockwise direction, carrying be rotated in a clockwise direction v gears 23 and 24 rolling locking planet gears-23 and 24 against rota- -movement of shaft- 17 and the rotation imparted to shaft 17 will be the resultant moor by locking planet gears 29 and 31.

tion derived from the two epicyclic gear trains.

l If the effective' couplings of the two gear trains are equal and pp osite, shaft 17 will remain stationary. If t ecoupling clfect of one of the gear trains is increased or decreased relative to the coupling eiect of the other gear train, the rotation of shaft 17 will be varied accordingly,

For restraining the rotation of planet gears 29 and 31 and planet gears 23 'and 24 relative to their respective sun gears, hydraulic means is employed and I have .shown in Fig.

' 2 a iuid conduit 43 which opens into the contacting surfaces of gears 31 and 28 and a similar conduit 44 leading away from these surfaces. Conduits 43 and 44 are part of a fluid circuit and are adapted to be filled with a suitable incompressible fluid, such as oil. When the oil in the circuit which includes conduits 43 and 44 isfree to circulate, relative rotation between gears 31 and 28 causes displacement of`oil in the line.V If, for example, block 21 is rotated in a clockwise direction, as viewed in Fig. 2, gears 29 and 31 are caused to roll around/'gear 28 in a clockwise direction and each of the gears rotates about its own axis in a clockwise direction. Assuming that the gear 28 is held stationary, oil will be carried around by the teeth of gear 31 from'conduit 44 and will be forced intoA conduit 43, thus causing a cntinuous ci rculaetion of oil in the oil circuit. Now, if the opening in conduit 43 is blocked, the oil therein will tend to be com ressed by the action of the gears, but since t eoil is-incompressible it exerts a force against gears 28 and 31 which prevents rotation of these gears relative toeach other.' Upon further rotation -of block 21, therefore, gear 28 will be forced to rotate therewith. If, however, the assage in conduit 43 is only partly closetl there` will be some'circulation .of oil and gear 28 will be caused to rotate in the same direction as block 21 `but at a lower velocity. By controlling the extent of restriction of passage 43,

therefore, gear 28 can be caused to rotatel at any velocity equal to or less than the velocity of block 21.

A similar conduit 46 is associated with planetlgear 29 and is adapted to control the actionof ear 28 relative to gear 29. Other conduits 4 and '48 extend to the planet gears 23 and 24 of the other epicyclicgear train. The fluid conduits extend thru block 21 and thru an extension block 49 rigidlysecured on block 21 to a sleeve valve 51 which is adapted to control all of the passages simultaneously.` Valve 51 has asliding -fit about sleeve 32 and is capableof longitudinal movement and rotational movement relative to sleeve 32. The outer surface of valve 51 is. provided with. a plurality of keys 52 which are slidably disposed within a plurality of splines 53 in block 49 so that valve 51 can be `In'entary relative to each other, that is,

moved longitudinally relative to block 49, but is prevented from rotating -with respect to block 49.

Attention is now directed to Fig. 7 .in which I have shown diagrammatically one arrangement of the fluid conduits relative to the other parts of the transmission. Valve 51 is provided with a pair of gates 54 which control the fluid which is adapted to restrain the epicyclic gear train of which gear 22 lis the sun gear and a pair of similar gates 56 for controlling the fluid acting upon the other epicyclic gear train. Valve 51, in the position shown, allows circulation of the fluid through the epicyclic gear train of which gear 28 is the sull gear and thc pathl of the fluid, assuming that gears 29 and 31 are rotating in a clockwise direction, may be traced from conduit 44, around gear 31, thru conduit 43, thru one ofthe gates 56 in valve 51,conduit 57, around gear 29, conduit 46, thru the other gate 56 and back to conduit 44. v

It 'willbe noticed that the path just traced is controlled by two valve gates 56 and that the same fluid,controls the restraint on -both gears 29 and 31. v'

A `'milar path can be provided to control the restraint on the other epicyclic gear train,

but for the purpose of illustrating an alternative arrangement', I have shown separate fluid paths for controlling leach of the gears 23 and 24. The iuid path controlling gear 23 can be traced from one of the gates 54,

thru conduit 47, around gear 23, thru conduit `58 back to gate 54. Thispath is shown obstructed at `gate 54. The fluid pathcontrolling gear 24 can be traced from the other gate 54, thru conduit 48, around gear 2 4, thruconduit 59 back to gate 54 and'this path is also obstructed at its associated gate 54.

`When valve 51 is in the position shown in Fi .'7, planet gears 29 and 31 are free to roll a out gear`28, but rolling movement of planet gears 23 and 24 about .gear 22 is re-v stricted by the obstructed 'fluid path leading to gears 23 and 24. Gear 22, therefore, is constrained to rotatev and the motion 1m'- fluid conduits controlling gear 28 will at firstv be obstructed a slight amount thereby causing the counter-clockwise rotation of gear 28VV to decrease and at the same time the Huid conduits controlling gear 22 will be opened slightly, thereby causing the clockwise rota- 56 are preferably so dis-l` to obstruct the paths rolled by gate 54 become ISS f lim-itin tion of gear 22 to decrease by a correspond.- ingly slight amount. The motion imparted to shaft 17 will be the resultant effect of the rotational mvement of both gears 22 and 28. As valve51 is moved further to the right the counterclckwise rotation of gear 28 and the clockwise rotation of gear 22 will be further decreased. Eventually, as valve 51 is moved still further to the right the effect of gear 28 on the rotation of yshaft 17 will be l equal and opposite to the effect of gear 22 andl both gears 22 and 28 and shaft 17 will be stationary. Now, as valve 51 is moved still- ,further to the ri l ht, gear 28 will be caused to rotate in a cloc wise direction and gear 22 will be caused to rotate in a counter clockwise direction'and shaft 17 will, therefore, rotate in a counterclockwise direction. At the position of valve 51 toward the right'A shaft l will rotate at its maximum velocity in a counterclockwise direction. Thus, it will be seen that shaft 17' can be caused to-rotate One end of lever 61 is conduits which control in either direction and at all intermediate values merely by shifting v'alve 51 tothe right or to the left.

For actuating or shifting valve 51, a lever 61- is provided which is pivoted about a pin 62 and which extends outside of housing 18.

provided with a yoke l 63 having projections thereon which-extend into a groove 64 formed on` valve 51. By swinging lever 61 about pivot 62 valve 51 is caused to slide longitudinally on sleeve 32 and thereby vary the relative position of the gates in valve 51 relative to the fluid conduits. If desired, any suitablel means, such as friction means, can be provided for maintaining' lever 61 in any one of its adjusted positions. f

-Normally housing 18 is completely filled or substantially filled with a suitable oil which serves to lubricat'e the gears as well as to maintain a constant supply of fluid in the the epicyclic gear trains. In order that oil will not escape from the opening thru which lever lextends,`

a fluid-tight joint 66 of any suitable type is provided between lever 61 and housing 18.

r The left hand side of housing 18, asnviewed in Fig. 1, is adaptedy to be coveredfby a suitable fluid-tight plate or by securing housing 18 to some part of the machine inyvhich thtransmission is to be used, such as the'crankcase of an automobile.

As block 2lrotates, oilLin housing 18. is constantly splashed against the upper side of housing 18 and an oil scoop 67 is secured to the interior of housing 18 and is disposed ad.

jacent the periphery-of block 21 tofcatch this' oil and v`deliver it into a conduit 68.. Conduit 68 communicates with the interi orof a conical cover plate 69 disposed over the end of block 49. When block 49 rotates, oil is carried by centrifugal action to all parts ofthe chamber formed between the block 49 and the conical cover 69 and this chamber is at. all

against a seat 73 which controls the branch` passage to the oil filled chamber. By employing a valve of this construction, oil can .be drawn inwardly into the conduits which control the epicyclicgear trains, butnone is permitted to .pass outwardly thru these valves. Thus, oil is automatically delivered to the conduits to whenever required. v When my transmission i's employed on an automobile, the customary clutch can be dispensed with, sinceshaft 17 can ybe held stationary merely by sliding valve 51 to the proper position. Shaft 16- can be connected directly to the crankshaft of the automobile engine and a starter gear can be secured on shaft 16 or disposed about block 21 which meshes with a ea-r of a starter motorlof any suitable type. `lVhen valve 51 is in that position which causes shaft 17 to remain stationary, shaft 16 can be rotated to start the motor without transmitting any motion of shaft 17. While a clutch is n'ot essential, however, one can be provided if desired without departing from the spirit of this invention.

VIn Figs. 8 to 10 I have shown a modification of the valves controlling the fluid content and of the actuating mechanism therefor. In this modification a separate valve is employed to control each fluid conduit, there being four of such valves. The valves are arranged in pairs and.; the actuating mechanism is` adapted to replenish the supply thereinactuate all of the valves simultaneously, the

valves in each pair being operable together and the operation of each pair of valves be; ing complementary to the operation of the other, so that one pair of valves opens the associated fluid conduits as the other pair closes the other Huid conduits. Thus, I have shown a pair of valves 77 and 78 and 81 respectively. Valve 77 is slidable and the gate 79 therein is adapted to be moved to` and from openings 83' in one of the fluid conduits and valve 78 is slidable in a similar manner to control openings 84,in one of the '-f other Huid conduits.

other, and as sleeve 884is moved toward the j right valves 77 and 78 move in the opposite direction,or toward each other. During this -Links 86 and 87 connect valves 77 and 78, respectively, to a sleeve 88 which is slidably movementof the .valves 77 and 78, their revIII- so cam member 108. When shaft 110 is rotated,

spective iiuid conduits are opened together, or are closed together, as the case may be.

sleeve 96 slidably disposed over sleeve 88, controls fluid conduits 97 and 98 in a similar manner in response to movement of sleeve 96.

'Y For actuating sleeve 88 'a lever 99 is provided which is pivoted about a pin 101. A yoke 102 is formed on one end of lever 99 whichv engages a groove 103 in, sleeve 88. By 'swinging lever 99 about pivot pin 101, sleeve 88 can be moved to the right or to the left to open or close valves 7 7 and 78. For actuating sleeve 96, ,a second lever 104 is provided,

which is also pivoted about pin 101 and this lever has a yoke 106 which engages a groove ,107 in sleeve 96.

For actuating levers 99 and'104 so that one set of valves opens while the other closes, a air of cam members 108 and 109 are provided which are secured to a shaft 110 journaled for rotational movement in bearin s 11.1 and 112. Cam member 108 has a suitable cam race 113 form'ed therein which engages a pin 114 extending from lever 99. Cam member 109 is provided with a similar cam race 116 which engages a pin 117 extending f rom lever 104, the cam race 116, however, being oppositely disposed relative t cam race- 113" on caml members 108 and 109 rotate therewith and cam member 108 causes valves-77 and 7 8 to be moved in one direction while cam member 109 causes valves 91 and 92 to be moved in the opposite direction, so that one set of' fluid conduits is being opened while the other set of iuid conduits is being closed.. Any suitable means, such as a lever 118, can be provided for imparting rotational movement to shaft 110. A cover plate 119 can be provided for the valves which has a function correspondingto that of cover plate69 described in connectionv with the other embodiment..

While I have referred to automobiles in the transmission, it` is to be understood that the transmissionisnotlimited to use on automobiles nor is it llmited to .use

on motive devices generally since it can adapted to a'wide variety of uses. Although Ihaveshown and described certain preferred 'embodimentsof my invention, I do not wlsh to be limited thereto, since the invention as de'- iined in the appendedyclai'ms can embodied- .in a plurality of other forms.

I claim: A l f 1. A transmission comprising a driving element including a h'ous1ng,"a drivenelement, a pair of hygraulic displacement gearv trains interposed tween saidvelements., located in and driven by said` housing,V of said gear trains aiording a dierent speed ratio between the elements, a unitin onel of said gear trains positively coupled to said driven element, and a hydraulically lretardd and each unit in each of said gear trains serving to con- A trol the combined coupling eect of both pair of similar valves 91 and 92 connected by vmeans of links 93 and 94, respectively, to a driven element, a unit in each of said gear trains adapted to be retarded to control the combined couplingeffect of both of said gear trains and means for retarding each of said units.

3. A transmission comprising a driving element including a housing, a driveng element, a pair of hydraulic displacement gear trains interposed between said elements, and located in and driven Aby said housing, each of said gear trains aording a different speed ratio between the elements, a unit in onev of said gear trains positively coupled to said driven element, a unit in each 4 of said gear trains adapted to be retarded .to control the combined coupling effect of both of said gear trains, hydraulicmeans for retarding each of said units and-means for varying the rretarding etiect of said hydraulic means.

4. A transmission comprising a driving Ielement including a housing, a driven element, a pair of hydraulic displacement gear trains interposed between said elements and located in and driven bysaid housing, each of said gear trains aiording 'a different speed ratio between the elements, a gear in one of g said gear trains positively coupled to said driven element, a gear in each of said gear trains adapted to be retarded to change the resultant coupling e'ect of both of said gear trainsv and hydraulic means adapted to be displaced by each of said retardable gears and serving to retard said' gears.

5. A transmission comprismg a drivmg element including a housing, a driven element, a pair of hydraulic displacement gear trains'interposed between said elements and located in and driven b said housing, each `of said gear trains aor ing a different speed ration` between'the elements, a gear in each'of said gear trains adapted tobe retarded' to change the resultant coupling effect of both of said gear trains, a gear in one'of said gear trains positively coupled to said driven element, hydraulic means adapted to be displaced by each of said retardable gears and serving to retard said gears and means for varying the displacement of said hydraulic means whereby the speed ratio between said elements-is varied accordingly.

6./A transmission comprising a driving element including a housln a drivenelement, a pair. of epicyclic hy raulic displace- I 11-3v ment gear trains interconnecting said ele ments and located in'and driven by said housing, each of said epicylic gear trains aiording a different speed ratio between `the elements, a gear in one of said gear trains positively coupledto saiddrivenl element a hydraulic displacement unit in each of sald ear trains capable when restricted of retar ing Vits associated gear tr'ain and means for restricting said units. 10 7. A transmission comprising a driving element including a-housm a driven element, a pair of epicyclic hygraulic dis lacement gear trains interconnecting Vsai elements and located in and drivenby said` housing, each of said epicylic gear trains affording a different speed ratio between the elements, a gear in one `of said gear trains positively coupled to said driven element, a hydraulic displacement unit in each o f said gear trains capable when restricted of retardlng its associated gear train, means for restrictin said unit and means for varyin thev restricting `means whereb the resu tant coupling effect of lboth of sa1d gear trains can 25 be varled.

8. A transmission comprising `a driving element including a housing, a driven element, a pair of gear trains interposed between said elements and located in and driven by 3 said housing, one of said gear trai'ns being rotated by the driving element in onedirection and the other of said gear trains being rotated by the driving` element in the reverse, direction, a unit in one of said gear trains positively coupled to said driven'elements s my hand.,

` and a hydraulically retardedunit in each of said gear trans servingto control the resultant coupling e'ectpf both gear trains.

9. A transmission comprising a ,driving elementk including@ hous1ng, al driven element, a pair of epicyclic gear trains interposed between said elements and located in and driven by said housing, one of saidv e icyclic gear trains being rotated b the driving element in one direction and rt e-other of said epicyclic gear trains being rotated by the driving element in the reverse direction a unit in one of said gear trains positively .coupled to said driven elements andV a hy draulically retarded unit in each of said epicyclic gear trains serving to control the re- Sultant coupling eiiect of both gear trains. lIn testimony whereof, I have hereunto set HOWARD w. Lewis. 

